Wireless IC device and component for wireless IC device

ABSTRACT

A wireless IC device includes a cutout portion having no aluminum-deposited film that is provided at an end of an article package made of an aluminum-deposited laminated film, and an electromagnetic coupling module is provided at the cutout portion. The electromagnetic coupling module and the aluminum-deposited film of the package define a wireless IC device. A loop electrode, which is a magnetic field transmission auxiliary radiator of the electromagnetic coupling module, is coupled to the aluminum-deposited film of the package. Thus, the article package functions as a radiator of an antenna.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a wireless IC device used for a radiofrequency identification (RFID) system that performs data communicationin a non-contact manner using electromagnetic waves, and a component forthe wireless IC device.

2. Description of the Related Art

In recent years, an article management system has used an RFID systemwhich includes a reader/writer that generates an induction field and awireless IC device that stores predetermined information allocated to anarticle, and non-contact communication is established between thereader/writer and the wireless IC device to transmit the informationtherebetween.

FIGS. 1A and 1B are views that show an example of a non-contact IC tag(wireless IC device) in which an IC tag label is attached to an IC tagantenna, which is described in Japanese Unexamined Patent ApplicationPublication No. 2003-243918. FIG. 1A is a plan view. FIG. 1B is anenlarged cross-sectional view taken along the line A-A in FIG. 1A. Thenon-contact IC tag antenna includes two separated antenna patterns 91and 92. The antenna patterns 91 and 92 are each made of a layer of metalthin films.

Antennas 101 and 102 are provided on a label base material 82 b of thenon-contact IC tag label 82, and an IC chip 85 is mounted thereon. Theantennas 101 and 102 of the non-contact IC tag label 82 are arranged tobe in contact with the antenna patterns 91 and 92 via an anisotropicconductive adhesive 84 to thereby define a non-contact IC tag 90.

A sealant film 83 is laminated on the label base material 82 b toprevent peeling of the IC tag label, and finally, an IC tag attachedpackage 81 is provided.

The non-contact IC tag disclosed in Japanese Unexamined PatentApplication Publication No. 2003-243918 and the package provided withthe non-contact IC tag have the following problems.

Because antenna patterns are formed in a process that is different fromthe process in which a package is formed, a process of producing anantenna is required. This causes the process to be lengthened andrequires an additional member which increases the production costs ofthe package.

To obtain a sufficient radiation characteristic, it is necessary toincrease the size of the antenna pattern, and, therefore, it isdifficult to attach a tag to a small article.

Because a tag is disposed on the base material of an article and anotherfilm covers the surface of the tag, the thickness of the IC tagformation portion is increased.

SUMMARY OF THE INVENTION

To overcome the problems described above, preferred embodiments of theinvention provide a wireless IC device that reduces production costs fora package, enables attachment to a small article, and reduces thethickness of the tag formation portion.

A wireless IC device according to a preferred embodiment of the presentinvention includes a high-frequency device, which is an electromagneticcoupling module or a wireless IC chip itself, said electromagneticcoupling module including a wireless IC and a power supply circuitsubstrate that is electrically connected or electromagnetically coupledto the wireless IC while being coupled to an external circuit, and aradiation electrode which is defined by a portion of an article andoperates as a radiator, wherein the high-frequency device is mounted onthe radiation electrode, and the radiation electrode is coupled to thehigh-frequency device.

With the configuration described above, for example, processes ormembers necessary to form the antenna pattern shown in FIGS. 1A and 1Bon an article are not required. Thus, the cost of providing a wirelessIC device for an article is not significantly increased.

In addition, because a portion of or substantially the entire articlemay be utilized as a radiator, a sufficient radiation characteristic maybe obtained even when it is attached to a relatively small article.

Furthermore, because the thickness of a portion on a base material ofthe article, at which the high-frequency device is provided, can bereduced, the high-frequency device portion does not significantlyprotrude from the article, and therefore, the appearance thereof is notadversely affected.

Moreover, by using the electromagnetic coupling module, impedancematching between the wireless IC chip and the radiation electrode may bedesigned within the power supply circuit substrate. Thus, it is notnecessary to limit the shape or material of the radiation electrode, andit may be applied to any article.

The radiation electrode includes a conductive portion having apredetermined area, wherein a cutout portion is provided at an edge ofthe conductive portion, and wherein the high-frequency device isarranged at the cutout portion while the high-frequency device iscoupled to the conductive portion at the cutout portion of theconductive portion. With the above-described configuration, thehigh-frequency device may preferably be arranged so as not to protrudefrom the profile of an article, and the conductive portion may beeffectively used as a radiator.

The radiation electrode includes a conductive portion having apredetermined area, wherein the conductive portion includes anon-conductive portion, and wherein the high-frequency device isarranged at an end in the non-conductive portion while thehigh-frequency device is coupled to the conductive portion around thenon-conductive portion. With the above-described configuration, thehigh-frequency device may preferably be arranged so as not to protrudefrom the profile of an article, and the conductive portion may beeffectively used as a radiator.

In addition, the wireless IC device according to preferred embodimentsof the invention preferably includes a loop electrode that is coupled tothe high-frequency device and that is directly electrically connected tothe radiation electrode, wherein the loop electrode is provided at amounting portion at which the high-frequency device (adjacent to amounting area) is mounted, such that a loop plane of the loop electrodeis arranged substantially in a direction of a plane of the radiationelectrode. With the above-described configuration, it is possible toeasily match the high-frequency device with the loop electrode, and theloop electrode is strongly coupled to the radiation electrode, such thata high gain may be obtained.

In addition, the wireless IC device according to preferred embodimentsof the present invention preferably includes a loop electrode providedat a mounting portion (adjacent to a mounting area) at which thehigh-frequency device is mounted, wherein the loop electrode is coupledto the high-frequency device and is electromagnetically coupled to theradiation electrode via an insulating layer. With the above-describedconfiguration, it is possible to easily match the high-frequency devicewith the loop electrode, and the loop electrode is insulated from directcurrent from the radiation electrode, such that it is possible toimprove resistance against static electricity.

A matching circuit is preferably provided between the mounting portionof the high-frequency device and the loop electrode, wherein thematching circuit directly electrically connects the high-frequencydevice with the loop electrode. With the above-described configuration,the matching circuit may be used as an inductor arranged to match animpedance between the radiation electrode and the high-frequency device.Thus, the degree of freedom to design impedance matching for a wirelessIC device is increased, and, in addition, the design is facilitated.

A resonant circuit and/or a matching circuit is provided in the powersupply circuit substrate. According to the above configuration,selectivity of frequency increases. Thus, the operating frequency of thewireless IC device may be mostly determined using the self-resonantfrequency. In accordance with the above, it is possible to transfer orexchange energy of a signal having a frequency used in an RFID systemwith high efficiency. This may improve the radiation characteristic ofthe wireless IC device.

In addition, by providing the matching circuit in the power supplycircuit substrate, it is possible to more efficiently exchange ortransfer energy of a signal having a frequency used in an RFID system.

A resonant frequency of the resonant circuit preferably substantiallycorresponds to a frequency of a signal exchanged by the radiationelectrode.

With this configuration, the radiation electrode is easily coupled to apower supply circuit portion and only needs to have a size correspondingto a required gain. It is not necessary to limit the shape or materialof the radiation electrode depending on a frequency used, and it may beused with any article.

The radiation electrode is preferably, for example, a metal film layerof an article package in which a sheet having a conductive layer isformed into a bag shape or a package shape. With the above-describedconfiguration, an article package having a metal film layer maypreferably be used without any change, and substantially the entirearticle operates as a radiator. Even when a plurality of articles areoverlapped, the ID of each article may be read.

The radiation electrode is preferably an electrode pattern provided, forexample, on a circuit substrate in an electronic device. With theabove-described configuration, the circuit substrate provided in theelectronic device may be used without any change, and mounting of thehigh-frequency device is facilitated.

The radiation electrode is preferably a metal plate provided on a rearsurface of a component, such as a liquid crystal display panel, in anelectronic device. With the above-described configuration, the componentprovided in the electronic device may preferably be used without anychange, and the size and cost thereof are not increased.

A resonant conductor that has a resonant frequency that is substantiallyequal to an operating frequency of the high-frequency device or afrequency that is close to the operating frequency is preferablyprovided, wherein the resonant conductor is coupled to thehigh-frequency device. With the above-described configuration, aradiation gain at the operating frequency of an RFID tag is increased,and an outstanding characteristic is obtained as an RFID. In addition,because the resonant frequency of the resonant conductor is notinfluenced by components mounted on the printed wiring substrate, thedesign thereof is facilitated.

The resonant conductor is preferably arranged substantially parallel toan edge portion of the radiation electrode, at which the cutout portionis provided. With the above-described configuration, coupling betweenthe resonant conductor and the radiation electrode is strong and,therefore, a high gain characteristic may be obtained.

The resonant conductor preferably has a length that is substantiallyequal to a side of the radiation electrode, which the resonant conductoris located adjacent to. With the above-described configuration, couplingbetween the resonant conductor and the radiation electrode is strongand, therefore, a high gain characteristic may be obtained.

The resonant conductor is preferably arranged so that a portion of theresonant conductor located adjacent to a location at which thehigh-frequency device is arranged is located substantially at thecenter. With the above-described configuration, coupling between theresonant conductor and the high-frequency device is strong and,therefore, a high gain characteristic may be obtained.

A plurality of the high-frequency devices are preferably provided, andthe resonant conductor is preferably coupled to each of thehigh-frequency devices. With the above-described configuration, thenumber of required resonant conductors may be reduced, and the areaoccupied on the printed wiring substrate may be reduced. Thus,manufacturing cost may be reduced.

The resonant conductor is preferably separable from a body that definesthe radiation electrode. With the above-described configuration, in themanufacturing process, a relatively large communication distance with areader/writer may be maintained, and after manufacturing, the size ofthe printed wiring substrate is not increased. In addition, it ispossible to provide communication as required by moving the resonantconductor close to the reader/writer.

The resonant conductor is preferably arranged in a margin portion of aprinted wiring substrate. With the above-described configuration, thecost of manufacturing the printed wiring substrate may be reduced.

A casing of a device on which the wireless IC device is mounted oranother component mounted on the device also preferably functions as theresonant conductor. With the above-described configuration, it ispossible to obtain a required gain even with a metal case or a mountedcomponent.

A component for a wireless IC device preferably includes ahigh-frequency device, which is an electromagnetic coupling module or awireless IC, including a wireless IC and a power supply circuitsubstrate that is electrically connected or electromagnetically coupledto the wireless IC while being coupled to an external circuit, and asubstrate on which the high-frequency device is mounted and whichincludes at least two linear electrodes, first ends of which are coupledto the high-frequency device.

With the above-described configuration, if the article includes only aconductor that operates as a radiator, by merely assembling thecomponent of a wireless IC device to that article, the article may beused as an RFID tag attached article.

In the linear electrode, the other ends of the linear electrodes arepreferably electrically connected to each other to define a loopelectrode. With the above-described configuration, the loop shape of theloop electrode is not influenced by the assembly process, such assoldering, and therefore, a highly accurate design with less variationin impedance may be achieved.

A wireless IC device preferably includes the component for a wireless ICdevice described above, and an article having a radiation electrode thatis electrically connected to the other ends of the at least two linearelectrodes to define a loop electrode. With the above-describedconfiguration, it is possible to easily form an RFID tag attachedarticle.

A wireless IC device preferably includes the component for a wireless ICdevice described above, and an article provided with a conductor that iscoupled to the loop electrode and operates as a radiator. With theabove-described configuration, it is possible to easily form an RFID tagattached article. In addition, when the article is an electroniccomponent, it is possible to reduce variations in characteristicthereof.

According to preferred embodiments of the present invention, thefollowing advantageous effects are obtained. For example, processes ormembers arranged to define an antenna pattern shown in FIGS. 1A and 1Bon an article are not required. Thus, there is no significant increasein the cost of providing a wireless IC device for an article.

In addition, because a portion of or the entire article may be used as aradiator, a sufficient radiation characteristic may be obtained evenwhen it is attached to a small article.

Furthermore, because the thickness of a portion on a base material ofthe article at which the high-frequency device is provided may bereduced, the high-frequency device portion does not significantlyprotrude, and therefore, the appearance is not adversely affected.

Moreover, by using the electromagnetic coupling module, impedancematching between the wireless IC chip and the radiation electrode may bedesigned within the power supply circuit substrate. Thus, it is notnecessary to limit the shape or material of the radiation electrode, andit may be applied to any articles.

Other features, elements, steps, characteristics and advantages of thepresent invention will become more apparent from the following detaileddescription of preferred embodiments of the present invention withreference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are views that show the configuration of a wireless ICdevice according to the related art.

FIG. 2 is a view that shows the configuration of a wireless IC deviceaccording to a first preferred embodiment of the present invention andthe configuration of an article provided with the wireless IC device.

FIGS. 3A and 3B are configuration diagrams of the wireless IC device,showing only a relevant portion of the article shown in FIG. 2.

FIG. 4 is a view that shows the configuration of a wireless IC deviceaccording to a second preferred embodiment of the present invention andthe configuration of an article provided with the wireless IC device.

FIG. 5 is a configuration diagram of the wireless IC device, showingonly a relevant portion of the article shown in FIG. 3.

FIGS. 6A and 6B are views that show the configuration of a wireless ICdevice according to a third preferred embodiment of the presentinvention and the configuration of an article provided with the wirelessIC device.

FIG. 7 is a view that shows the configuration of a wireless IC deviceaccording to a fourth preferred embodiment of the present invention andthe configuration of an article provided with the wireless IC device.

FIGS. 8A and 8B are a center cross-sectional view that is taken alongthe line passing a main portion of the wireless IC device and apartially enlarged plan view of the main portion of the wireless ICdevice.

FIGS. 9A and 9B are views that show the configuration of a wireless ICdevice according to a fifth preferred embodiment of the presentinvention.

FIG. 10 is an external perspective view of an electromagnetic couplingmodule used for a wireless IC device according to a sixth preferredembodiment of the present invention.

FIG. 11 is an exploded view of the internal configuration of a powersupply circuit substrate of an electromagnetic coupling module.

FIG. 12 is an equivalent circuit diagram that includes the power supplycircuit substrate and a cutout portion of a metal film.

FIG. 13 is a view that shows the configuration of a wireless IC deviceaccording to a seventh preferred embodiment of the present invention andthe configuration of an article provided with the wireless IC device.

FIG. 14 is a cross-sectional view of a main portion of the wireless ICdevice.

FIG. 15 is an exploded perspective view of a power supply circuitsubstrate of a wireless IC device according to an eighth preferredembodiment of the present invention.

FIG. 16 is an equivalent circuit diagram of a main portion of thewireless IC device.

FIGS. 17A and 17B are plan views of an electromagnetic coupling moduleused for a wireless IC device according to a ninth preferred embodimentof the present invention.

FIGS. 18A and 18B are views that show the configuration of a wireless ICdevice according to a tenth preferred embodiment of the presentinvention.

FIGS. 19A and 19B are views that show configurations of a wireless ICdevice according to an eleventh preferred embodiment of the presentinvention.

FIG. 20 is a view that shows the configuration of another wireless ICdevice according to the eleventh preferred embodiment of the presentinvention.

FIGS. 21A and 21B are views that show configurations of another wirelessIC device according to the eleventh preferred embodiment of the presentinvention.

FIG. 22 is a view that shows the configuration of a wireless IC deviceaccording to a twelfth preferred embodiment of the present invention.

FIGS. 23A and 23B are views that show configurations of a wireless ICdevice according to a thirteenth preferred embodiment of the presentinvention.

FIG. 24 is a plan view that shows the configuration of a wireless ICdevice according to a fourteenth preferred embodiment of the presentinvention.

FIG. 25 is a plan view that shows the configuration of a wireless ICdevice according to a fifteenth preferred embodiment of the presentinvention.

FIG. 26 is a plan view that shows the configuration of a wireless ICdevice according to a sixteenth preferred embodiment of the presentinvention.

FIGS. 27A and 27B is a perspective view of a cellular phone terminalprovided with a wireless IC device according to a seventeenth preferredembodiment of the present invention and a cross-sectional view of a mainportion of an internal circuit substrate.

FIG. 28 is a plan view that shows the configuration of a component for awireless IC device according to an eighteenth preferred embodiment ofthe present invention.

FIG. 29 is a plan view that shows a wireless IC device that uses thecomponent for a wireless IC device according to the eighteenth preferredembodiment of the present invention.

FIG. 30 is a view that shows an example in which a main portion of awireless IC device is formed within a ground electrode formation area ona printed wiring substrate.

FIGS. 31A and 31B are plan views that show the configuration of acomponent for a wireless IC device according to a nineteenth preferredembodiment and the configuration of a wireless IC device provided withthat component.

FIGS. 32A and 32B are plan views that show the configuration of acomponent for a wireless IC device according to a twentieth preferredembodiment of the present invention.

FIG. 33 is a plan view that shows the configuration of a wireless ICdevice provided with the component for a wireless IC device according tothe twentieth preferred embodiment of the present invention.

FIG. 34 is a plan view that shows the configuration of a component for awireless IC device according to a twenty-first preferred embodiment ofthe present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS First Preferred Embodiment

FIG. 2 is an external perspective view that shows the configuration of awireless IC device according to a first preferred embodiment of thepresent invention and the configuration of an article provided with thewireless IC device. The article 70 is, for example, a packaged snack,such as potato chips. An article package 60 is a package that preferablyincludes an aluminum-deposited laminated film formed into a bag shape.

A cutout portion (a portion at which aluminum is not vapor-deposited) 61is provided at an edge portion of the article package 60, and anelectromagnetic coupling module 1 is arranged in the cutout portion 61.

FIGS. 3A and 3B are views that show the configuration of a wireless ICdevice and only a relevant portion of the article 70 shown in FIG. 2. InFIGS. 3A and 3B, a radiation electrode 8 corresponds to analuminum-deposited layer of the aluminum-deposited laminated film of thearticle package 60 shown in FIG. 2. The cutout portion (electrodenon-formation portion) 61 of the radiation electrode 8 includes a loopelectrode 7 disposed therein, and the electromagnetic coupling module 1is mounted at the cutout portion 61 so as to be coupled to the loopelectrode 7. The loop electrode 7 is patterned when aluminum depositionof the aluminum-deposited laminated film is performed. Alternatively, aconductive pattern may be formed by printing in a different process fromthe process of aluminum deposition.

FIG. 3B schematically shows an example of a distribution ofelectromagnetic field that is generated in the radiation electrode 8when the loop electrode 7 is provided as a transmission auxiliaryradiator. In FIG. 3B, the broken line represents the loop of a magneticfield H, and the solid line represents the loop of an electric field E.The loop electrode 7 is applied as a magnetic field transmissionauxiliary radiator. The magnetic field H generated by the loop electrode7 substantially perpendicularly intersects the radiation electrode toinduce the electric field E. The electric field loop induces a magneticfield loop, and the chain of that action extends the distribution ofelectromagnetic field.

This example is described using the loop electrode 7 as a transmissionauxiliary radiator. When the loop electrode 7 is applied as a receptionauxiliary radiator as well, a similar action may be achieved to obtain ahigh gain.

In this manner, when the article includes a conductive portion having apredetermined area and the conductive portion functions as a radiator,and when a large number of the articles are overlapped, chain inductionof the electric field and magnetic field propagates among the articles.Thus, even when a large number of articles are overlapped, the wirelessIC device operates to obtain a high gain. For example, when the antennaof a reader/writer is brought into close proximity to a portion of apile of packed potato chips, IDs of all of the pile of packed potatochips may be read.

Note that the electromagnetic coupling module 1 shown in FIGS. 3A and 3Bincludes a wireless IC chip, which will be described later, and a powersupply circuit substrate that is connected to the wireless IC chip andthat is coupled to an external circuit, i.e., the loop electrode 7, andthe radiation electrode 8 via the loop electrode 7. The wireless IC chipand the power supply circuit substrate may be connected electrically ormay be coupled electromagnetically. When they are coupledelectromagnetically, a capacity is provided between connectionelectrodes thereof with a dielectric thin film, or other suitableelement. By capacitively coupling the wireless IC chip and the powersupply circuit substrate, it is possible to prevent the wireless IC chipfrom being broken by static electricity.

In addition, when the power supply circuit substrate is provided, twoelectrodes of the power supply circuit substrate are coupledelectromagnetically to both ends of the loop electrode 7. In addition,the electromagnetic coupling module 1 may be replaced with a singlepiece of wireless IC chip. In this case, two electrodes of the wirelessIC chip may be directly connected to both ends of the loop electrode 7.In any case, because the loop electrode 7 is separated from a directcurrent of the radiation electrode 8, the wireless IC device isadvantageously resistant against static electricity.

In addition, the loop electrode 7 may have any shape as long as the loopelectrode 7 is arranged so as to couple input and output terminals ofthe electromagnetic coupling module 1.

Second Preferred Embodiment

FIG. 4 is an external perspective view that shows the configuration of awireless IC device according to a second preferred embodiment of thepresent invention and the configuration of an article provided with thewireless IC device. The article 71 is, for example, a packaged snack. Anarticle package 60 is formed so that an aluminum-deposited laminatedfilm has a bag shape.

In the example shown in FIG. 2, the electromagnetic coupling module isarranged at an edge portion of the article package, whereas in FIG. 4,the electromagnetic coupling module 1 is provided at a portion of thearticle package 60, away from the edge portion of the article package60. The article package 60 is preferably made of an aluminum-depositedlaminated film. A portion of the article package 60, at which aluminumis not deposited, is provided as a non-conductive portion 62. Theelectromagnetic coupling module 1 is arranged inside the non-conductiveportion 62 and at an end of the non-conductive portion 62.

FIG. 5 is a view that shows a portion at which the electromagneticcoupling module 1 shown in FIG. 4 is mounted. In FIG. 5, theconfiguration of the loop electrode 7 and electromagnetic couplingmodule 1 is similar to that shown in FIGS. 3A and 3B in the firstpreferred embodiment. The radiation electrode 8 corresponds to thealuminum-deposited layer of the aluminum-deposited laminated film of thearticle package 60. The loop electrode 7 and the electromagneticcoupling module 1 are arranged inside the non-conductive portion 62 sothat the loop electrode 7 is preferably located adjacent to three sidesof the radiation electrode 8.

With the above-described configuration, the loop electrode 7 operates asa magnetic field transmission auxiliary radiator. The loop electrode 7is coupled to the radiation electrode 8 and, similar to that shown inFIGS. 3A and 3B, the radiation electrode 8 operates as a radiator of anantenna.

Note that when the area of the non-conductive portion 62 is set to besubstantially equal to the area occupied by the loop electrode 7 and theelectromagnetic coupling module 1 and the loop electrode 7 and theelectromagnetic coupling module 1 are arranged inside the non-conductiveportion 62, the magnetic field of the loop electrode 7 is coupled to theradiation electrode 8 at four sides. Therefore, an electromagnetic fieldinduced by the radiation electrode 8 is cancelled to reduce the gain.Thus, it is important that the area of the non-conductive portion 62 issufficiently greater than the area occupied by the loop electrode 7 andthe electromagnetic coupling module 1, and the loop electrode 7 islocated adjacent to the radiation electrode 8 at only one side, twosides, or three sides.

Third Preferred Embodiment

FIG. 6B shows the configuration of a main portion of a wireless ICdevice according to a third preferred embodiment of the presentinvention. FIG. 6A is an external view of an article provided with thewireless IC device. In FIG. 6A, the article 72 is configured such that amain portion 6 of the wireless IC device is provided on the metalsubstantially planar body 63. The metal substantially planar body 63preferably is a plate-shaped or sheet-shaped article that includes ametal layer therein or a metal plate itself.

The main portion 6 of the wireless IC device has a tuck index shape asshown in FIG. 6B and includes an adhesive layer on the inner surface ofan insulative sheet 64. The loop electrode 7 and the electromagneticcoupling module 1 are sandwiched by the insulative sheet 64. Theconfiguration of the loop electrode 7 and electromagnetic couplingmodule 1 is similar to that shown in FIGS. 3A and 3B.

Then, the loop electrode 7 is attached so as to be located adjacent toan edge of the metal plane body 63 shown in FIG. 6A, that is, such thata tuck index is adhered only to the edge.

Even when no cutout is provided at an edge portion of the conductiveportion as described above, by arranging the loop electrode 7 of themain portion 6 of the wireless IC device close to the edge portion ofthe metal plane body 63, the loop electrode 7 and the metal plane body63 are coupled to each other. Thus, the metal plane body 63 operates asa radiator of an antenna.

Fourth Preferred Embodiment

A wireless IC device according to a fourth preferred embodiment of thepresent invention will be described with reference to FIG. 7 and FIGS.8A and 8B. The wireless IC device according to the fourth preferredembodiment is preferably applied to a recording medium having a metalfilm, such as a DVD, for example.

FIG. 7 is a plan view of a DVD disk. FIG. 8A is a center cross-sectionalview that is taken along the line passing through the main portion 6 ofthe wireless IC device, and FIG. 8B is a partially enlarged plan view ofthe main portion 6 of the wireless IC device. However, thecross-sectional view of FIG. 8A is exaggerated in size in the thicknessdirection.

As shown in FIG. 7 and FIG. 8A, the DVD disc 73 is formed by adheringtwo disc-shaped discs, one of the discs has a metal film 65 formedthereon, and the main portion 6 of the wireless IC device is provided atportion of the inner peripheral edge of the metal film 65.

As shown in FIG. 8B, a substantially C-shaped cutout portion 66 isprovided at a portion of the inner peripheral edge of the metal film 65.The cutout portion 66 is not a cutout of the disc but is a cutoutportion of the metal film. The electromagnetic coupling module 1 isarranged so that two terminals of the electromagnetic coupling module 1,defined by the substantially C-shaped cutout portion, face twoprotruding ends facing each other. The inner peripheral end (portionindicated by the arrow in the drawing) of the substantially C-shapedcutout portion functions as a loop electrode.

Fifth Preferred Embodiment

FIGS. 9A and 9B are views that show the configuration of two wireless ICdevices according to a fifth preferred embodiment of the presentinvention. The fifth preferred embodiment provides a matching circuitbetween a mounting portion of a high-frequency device and a loopelectrode. The matching circuit establishes direct electrical connectionbetween the high-frequency device and the loop electrode.

In FIG. 9A, the metal film 65 is formed into a sheet material or a platematerial, and functions as a radiator. By providing a cutout portion 66at a portion of the metal film 65, the portion extending along the innerperipheral edge of the cutout portion 66 functions as a loop electrode.

The matching circuit 67 defined by a meandering electrode and metal filmportions 65 a and 65 b, which are mounting portions for thehigh-frequency device, e.g., an electromagnetic coupling module or awireless IC chip, are provided inside the cutout portion 66.

By providing the matching circuit 67 in this manner, the wireless ICchip may be directly mounted at the metal film portions 65 a and 65 b.Note that when the wireless IC chip is directly mounted on the loopelectrode, the loop electrode including the matching circuit 67substantially determines the operating frequency of the wireless ICdevice.

In FIG. 9B, the radiation electrode 8 includes the non-conductiveportion 62 provided therein, and the loop electrode 7, the matchingcircuit 67, and the electromagnetic coupling module 1 are arrangedinside the non-conductive portion 62 such that the loop electrode 7 islocated adjacent to three sides of the radiation electrode 8. Theconfiguration of the matching circuit 67 and mounting portion of theelectromagnetic coupling module 1 is similar to that shown in FIG. 9A.

With the above-described configuration, the loop electrode 7 operates asa magnetic field radiator. The loop electrode 7 is coupled to theradiation electrode 8 and, due to an action similar to that shown inFIGS. 3A and 3B, the radiation electrode 8 functions as a radiator.

Note that the metal film 65 in FIG. 9A or the radiation electrode 8 inFIG. 9B may preferably be, for example, a solid electrode that isprovided on the circuit substrate inside a cellular phone terminal.

Sixth Preferred Embodiment

FIG. 10 is an external perspective view of an electromagnetic couplingmodule 1 used for a wireless IC device according to a sixth preferredembodiment of the present invention. The electromagnetic coupling module1 may be applied to the wireless IC devices in the other preferredembodiments. The electromagnetic coupling module 1 includes a wirelessIC chip 5 and a power supply circuit substrate 4. The power supplycircuit substrate 4 matches an impedance between the metal film 65,which functions as a radiator, and the wireless IC chip 5, and alsofunctions as a resonant circuit.

FIG. 11 is an exploded view that shows the configuration of the insideof the power supply circuit substrate 4. The power supply circuitsubstrate 4 includes a multilayer substrate formed by laminating aplurality of dielectric layers in which electrode patterns arerespectively provided. Wireless IC chip mounting lands 35 a to 35 d areprovided on the uppermost dielectric layer 41A. A capacitor electrode 51that is electrically connected to the wireless IC chip mounting land 35b is provided on the dielectric layer 41B. A capacitor electrode 53 isprovided on the dielectric layer 41C and defines a capacitor C1 with thecapacitor electrode 51. Inductor electrodes 45 a and 45 b are providedon each of the dielectric layers 41D to 41H. The inductor electrodes 45a and 45 b provided in the plurality of layers form a spiral shape, anddefine inductors L1 and L2 that are strongly inductively coupled to eachother. In addition, a capacitor electrode 54 is provided on thedielectric layer 41F and is electrically connected to the inductor L1.The capacitor electrode 54 is arranged between the two capacitorelectrodes 53 and 55 to define a capacitor. In addition, a capacitorelectrode 55 is provided on the dielectric layer 41H and is electricallyconnected to the capacitor electrode 53. Via holes 42 a to 42 i arearranged to electrically connect the electrodes on different dielectriclayers.

The capacitor electrode 55 faces an end 65 b of the metal film, which isarranged at the cutout portion of the metal film 65 shown in FIGS. 8Aand 8B. A capacitor is provided between the end 65 b and the capacitorelectrode 55. In addition, the inductor electrodes 45 a and 45 b areelectromagnetically coupled to the metal film portion 65 a.

FIG. 12 is an equivalent circuit diagram that includes the power supplycircuit substrate and the cutout portion of the metal film shown in FIG.11. In FIG. 12, the capacitor C1 is a capacitor generated between thecapacitor electrodes 51 and 53 shown in FIG. 11, the capacitor C2 is acapacitor generated between the capacitor electrode 54 and the capacitorelectrodes 53 and 55 shown in FIG. 11, and the inductors L1 and L2 areprovided by the inductor electrodes 45 a and 45 b shown in FIG. 11. Themetal film 65 shown in FIG. 12 is a loop that extends along the innerperipheral edge of the cutout portion 66 shown in FIGS. 8A and 8B. Thecapacitor electrode 55 is capacitively coupled to one end 65 b, and theother end 65 a is electromagnetically coupled to the inductors L1 andL2. Thus, the loop that extends along the inner peripheral edge of thecutout portion 66 functions as a loop electrode.

Note that in the fourth preferred embodiment, the loop that extendsalong the inner peripheral end of the cutout portion of the metal filmfunctions as the loop electrode. Alternatively, as shown in FIGS. 3A and3B, it is applicable that a loop electrode is provided inside the cutoutportion, and the electromagnetic coupling module 1 that includes thewireless IC chip 5 and the power supply circuit substrate 4 are mountedto the loop electrode. In this case, the loop electrode and the metalfilm 65 are coupled, and the metal film 65 functions as a radiator.

In the power supply circuit substrate 4, a resonant frequency isdetermined in a resonant circuit defined by the inductance elements L1and L2 and its stray capacitance. The frequency of a signal radiatedfrom the radiation electrode is substantially determined based on aself-resonant frequency of the resonant circuit.

The electromagnetic coupling module 1, which is arranged so that thewireless IC chip 5 is mounted on the power supply circuit substrate 4,receives a high-frequency signal (for example, a UHF frequency band)radiated from a reader/writer (not shown) through the radiationelectrode, resonates the resonant circuit in the power supply circuitsubstrate 4 and then supplies only a reception signal of a predeterminedfrequency band to the wireless IC chip 5. On the other hand, theelectromagnetic coupling module 1 extracts a predetermined amount ofenergy from the reception signal, matches information stored in thewireless IC chip 5 with a predetermined frequency in the resonantcircuit using the extracted energy as a driving source, and thentransmits the information to the radiation electrode. The information isfurther transmitted from the radiation electrode to the reader/writer.

In this manner, by providing the resonant circuit in the power supplycircuit substrate, frequency selectivity is significantly increased.Thus, the operating frequency of the wireless IC device may be primarilydetermined using the self-resonant frequency. Accordingly, it ispossible to exchange or transfer energy of a signal of a frequency usedin an RFID system with high efficiency. In addition, it is possible toset an optimum resonant frequency corresponding to the shape and size ofa radiator. This may improve the radiation characteristic of thewireless IC device.

Note that the wireless IC chip and the mounting lands of the powersupply circuit substrate may be electrically connected or capacitivelycoupled through insulation.

In addition, by providing the matching circuit in the power supplycircuit substrate, it is possible to exchange energy of a signal of afrequency used in an RFID system with high efficiency.

Seventh Preferred Embodiment

FIG. 13 is a perspective view that shows the configuration of a mainportion of a wireless IC device according to a seventh preferredembodiment of the present invention. FIG. 14 is an enlarged partiallycross-sectional view of FIG. 13.

In FIG. 13, a base material 10 is the base material of an article forwhich the wireless IC device is provided and is preferably, for example,an aluminum-deposited laminated film. On the aluminum-deposited layer ofthe base material 10, a loop electrode 30 that is open at the cutoutportion described in the first preferred embodiment or in apredetermined portion of the non-conductive portion described in thesecond preferred embodiment. An inductor electrode 20 and a capacitorelectrode 25 are disposed above the open two ends 30 a and 30 b via aninsulating layer. The inductor electrode 20 has a substantially spiralshape and, as will be described below, the inside end is connected tothe capacitor electrode 25.

The wireless IC chip 5 is mounted at the ends of the inductor electrode20 and capacitor electrode 25, as shown in the enlarged view in FIG. 13.That is, the wireless IC chip mounting land 35 a is provided at the endof the inductor electrode 20 and the wireless IC chip mounting land 35 bis provided at the end of the capacitor electrode 25, and, furthermore,the mounting lands 35 c and 35 d are provided. Then, the wireless ICchip 5 is mounted.

FIG. 14 is a cross-sectional view that is taken along the line II-II inFIG. 13. As shown in FIG. 14, the inductor electrode 20 faces the end 30a of the loop electrode. A wire 21 connects the inside end of theinductor electrode 20 shown in FIG. 13 to the capacitor electrode 25.

In this manner, capacitors and inductors arranged to match the impedanceand adjust the resonant frequency may be provided on the side of thebase material 10 of an article, and the wireless IC chip 5 may bedirectly mounted.

Eighth Preferred Embodiment

FIG. 15 is an exploded perspective view of a power supply circuitsubstrate 40 of a wireless IC device according to an eighth preferredembodiment of the present invention. In addition, FIG. 16 is anequivalent circuit diagram thereof.

The power supply circuit substrate 40 includes a multilayer substrateformed by laminating a plurality of dielectric layers in which electrodepatterns are respectively provided. Wireless IC chip mounting lands 35 ato 35 d are provided on the uppermost dielectric layer 41A. A capacitorelectrode 51 that is electrically connected to the wireless IC chipmounting land 35 b is provided on the dielectric layer 41B. A capacitorelectrode 53 is provided on the dielectric layer 41C and defines acapacitor C1 with the capacitor electrode 51. Inductor electrodes 45 aand 45 b are provided on each of the dielectric layers 41D to 41H. Theinductor electrodes 45 a and 45 b provided on these layers define aninductor L1 that has a substantially spiral shape. In addition, acapacitor electrode 54 is provided on the dielectric layer 41F and iselectrically connected to the inductor L1. The capacitor electrode 54 isdisposed between the two capacitor electrodes 53 and 55 (or 56) todefine a capacitor. In addition, a capacitor electrode 55 is provided onthe dielectric layer 41H and is electrically connected to the capacitorelectrode 53.

Capacitor electrodes 56 and 57 are provided on a dielectric layer 41I.The capacitor electrode 56 is electrically connected to the capacitorelectrodes 53 and 55. In addition, the capacitor electrode 57 iselectromagnetically coupled to the inductor electrodes 45 a and 45 b.

Inductor electrodes 46 and 47 are provided on each of dielectric layers41J to 41N. The inductor electrodes 46 and 47 define a loop electrode L2that is preferably wound multiple times. Via holes 42 a to 42 m arearranged to electrically connect the electrodes of the differentdielectric layers.

That is, the power supply circuit substrate 40 is configured such thatthe loop electrode is included in the power supply circuit substrate 4shown in FIG. 11. Thus, by providing the electromagnetic couplingmodule, which is formed by mounting the wireless IC chip on the powersupply circuit substrate 40, to an article, the wireless IC device maybe provided, and it is not necessary to provide a loop electrode on thearticle side.

In FIG. 16, the capacitor C1 is a capacitor generated between thecapacitor electrodes 51 and 53 shown in FIG. 15, the capacitor C2 is acapacitor generated between the capacitor electrode 54 and the capacitorelectrodes 53 and 55 shown in FIG. 15, the inductors L1 a and L1 b arerespectively defined by the inductor electrodes 45 a and 45 b shown inFIG. 15, and the inductor L2 is defined by the inductor electrodes 46and 47 shown in FIG. 15.

Ninth Preferred Embodiment

FIGS. 17A and 17B are plan views of an electromagnetic coupling moduleused for a wireless IC device according to a ninth preferred embodimentof the present invention. In FIG. 17A, a loop electrode 12 and wirelessIC chip mounting lands are provided on the substrate 11 by an electrodepattern, and the wireless IC chip 5 is mounted.

In the eighth preferred embodiment shown in FIG. 15, the capacitors andinductors arranged to match impedance and adjust resonant frequency areprovided on the power supply circuit substrate together with the loopelectrode, whereas in the ninth preferred embodiment shown in FIGS. 17Aand 17B, the loop electrode and the wireless IC chip are integrated.

As shown in FIG. 17B, spiral electrode patterns are respectivelyprovided on the top and bottom surfaces of the substrate 11, capacitorelectrodes provided on the top and bottom surfaces of the substrate 11are arranged at the approximate center of each of the spiral electrodepattern, and then the line on the top surface and the line on the bottomsurface are connected via the capacitors. That is, the desired linelength and inductance are obtained within a limited area by utilizingboth surfaces of the substrate 11 to thereby define the loop electrode12.

Two electromagnetic coupling modules 2 and 3 shown in FIGS. 17A and 17Bare each arranged adjacent to a metal film of an article, whichfunctions as a radiator, or a metal plate such that the radiationelectrode is capacitively coupled to the loop electrode 12. With thisconfiguration, it is possible to utilize the metal film of the articleor the metal plate as a radiator of an antenna without providing anyspecific circuit on the article side, as in the case of the first andsecond preferred embodiments.

Tenth Preferred Embodiment

FIGS. 18A and 18B are views that show the configuration of a wireless ICdevice according to a tenth preferred embodiment of the presentinvention. In the first to ninth preferred embodiments, the articlepackage 60, the metal substantially planar body 63, and the metal film65, in which a conductive member extends in a substantially planarmanner, function as a radiator, whereas in the tenth preferredembodiment, a resonant conductor that is insulated from a planarconductive member and that functions as a resonator is provided.

FIG. 18A is a plan view of a conductive pattern on a printed wiringsubstrate when an RFID tag is provided on the printed wiring substrate.In addition, FIG. 18B is a plan view of a wireless IC device thatfunctions as an RFID tag, which is configured so that theelectromagnetic coupling module 1 including a wireless IC chip and apower supply circuit substrate is mounted on the printed wiringsubstrate.

A metal film 65, which is used as a ground electrode of another circuit,is provided on the upper surface of the printed wiring substrate 80. Themetal film 65 partially defines a cutout portion (metal filmnon-formation portion) 66, and the metal film portions 65 a and 65 b,which define a mounting portion for a high-frequency device(electromagnetic coupling module or wireless IC chip), are provided inthe cutout portion 66.

As shown in FIG. 18B, by mounting the high-frequency device 1 on themetal film portions 65 a and 65 b, the portion that extends along theinner peripheral edge of the cutout portion 66 functions as a loopelectrode. The mounting area of the high-frequency device 1 defines amain portion 6 of the wireless IC device.

A resonant conductor 68 that is coupled to the high-frequency device 1is provided on the upper surface of the printed wiring substrate 80. Theresonant conductor 68 has determined dimensions (particularly, length)such that the resonant frequency is a frequency used in an RFID tag or afrequency thereabout. For example, when a glass epoxy substrate is usedand the operating frequency is a UHF band, the length of the resonantconductor 68 needs to be only several tens of centimeters so as tooperate as a both-end-open half-wavelength resonator.

The resonant conductor 68 is arranged so that the approximate center islocated adjacent to the loop electrode of the main portion 6 of thewireless IC device, so as to be coupled to the high-frequency device 1.In addition, in this preferred embodiment, the resonant conductor 68 isarranged along one side of the metal film 65 in an insulated manner.

In FIG. 18B, the arrow J shown in the resonant conductor 68 typicallyrepresents an electric current path, the arrow EF typically representsan electric field distribution, and the arrow MF typically represents amagnetic field distribution. In this manner, the magnitude of anelectric current that flows through the resonant conductor 68 is at amaximum around the approximate center. Thus, the magnetic fieldgenerated at the resonant conductor 68 is at a maximum around theapproximate center, and the resonant conductor 68 is stronglymagnetically coupled to the portion of the loop electrode, extendingalong the inner peripheral edge of the cutout portion 66.

When the resonant conductor 68 is resonated in the vicinity of theoperating frequency of the RFID tag, an electric current that flowsthrough the resonant conductor 68 and a voltage generated across bothends of the resonant conductor 68 increases. Due to the magnetic fieldand electric field generated by the electric current and a voltage, theresonant conductor 68 is coupled to the metal film 65.

The peak of a voltage of a standing wave generated at the resonantconductor 68 is provided at an end of the resonant conductor 68. In thispreferred embodiment, because the length of the resonant conductor 68 issubstantially equal to one end of the metal film 65 that functions as aradiator, the resonant conductor 68 is strongly coupled to the metalfilm 65. Thus, a high gain is obtained. With the arrangement describedabove, it is possible to obtain an excellent characteristic as an RFIDtag.

When no resonant conductor 68 is provided, resonance needs to beperformed only in the metal film 65 at the operating frequency of anRFID tag. However, due to restrictions on the size of the metal film 65and depending on the components mounted on the printed wiring substrate,the resonant frequency shifts. According to the present preferredembodiment, because the metal film 65 is separated from the resonantconductor 68, the resonant conductor 68 may be designed as a singleunit, and a shift in resonant frequency due to mounted components doesnot occur.

Note that in the tenth preferred embodiment, only the metal film, as aground electrode, and the resonant conductor are described as anelectrode pattern provided on the printed wiring substrate. However, anelectrode pattern is appropriately determined based on a circuit to beformed and an electronic component to be mounted. This also applies toother preferred embodiments described below.

When an RFID tag is provided on the above-described printed wiringsubstrate, and information such as manufacturing process history iswritten to the RFID tag, it is possible to manage, for example, aprocess of mounting components to a printed wiring substrate. Forexample, when a malfunction of an electronic component is detected in alot, it is possible to withdraw only a small number of electronicdevices that have the malfunctioning electronic component included inthat lot. In addition, post-sales support and maintenance when theproduct is in operation in the market may be quickly performed, andrecycling of the resource after disposal will be simplified.

In addition, after process management has ended, a portion of theprinted wiring substrate, defining the resonant conductor 68, may beremoved. By so doing, the size of the printed wiring substrate may bereduced, and it is possible to reduce the size of a product withoutlosing the function of an RFID tag. Because the resonant conductor 68 ispresent at the time of process management, data may be read even whenthe output level of a reader/writer is relatively low. By lowering theoutput of an RF signal, it is possible to suppress a malfunction of acontrol device, a characteristic measurement device, and other suitabledevice. Furthermore, after the resonant conductor 68 is removed, themetal film 65 also functions as a radiator. Thus, communication is stillpossible although the communicable distance with a reader/writer isreduced.

When the printed wiring substrate is conveyed in a general manufacturingprocess, rails may be arranged on both sides of the printed wiringsubstrate and then the printed wiring substrate may be conveyed on therails. In order to prevent breakage of the portions that contact therails, the printed wiring substrate has a margin portion that will beremoved. If the resonant conductor 68 is provided at the margin portion,wasted space of the printed wiring substrate is significantly reduced.

Note that the metal film 65, which is a ground electrode, may beprovided in a plurality of layers of the printed wiring substrate. Inthis case, the region of the cutout portion 66 in each layer is providedas a metal film non-formation portion so that a magnetic flux passestherethrough.

According to this preferred embodiment, a radiation gain at theoperating frequency of an RFID tag increases and outstandingcharacteristics of an RFID are obtained. In addition, because theresonant frequency of the resonant conductor is not influenced bycomponents mounted on the printed wiring substrate, the design isfacilitated.

Eleventh Preferred Embodiment

FIG. 19A to FIG. 21B are views that show some configurations of awireless IC device according to an eleventh preferred embodiment of thepresent invention. Each of FIGS. 19A to 21B is a plan view of a wirelessIC device such that an RFID tag is provided on a printed wiringsubstrate.

In the examples shown in FIGS. 19A and 19B, the metal film 65, which isused as a ground electrode for another circuit, is provided on the uppersurface of the printed wiring substrate 80. The metal film 65 partiallydefines a cutout portion (metal film non-formation portion), and ahigh-frequency device (electromagnetic coupling module or wireless ICchip) is mounted inside the cutout portion, so that the main portion 6of the wireless IC device similar to that shown in FIGS. 18A and 18B isprovided.

The configuration differs from the configuration shown in FIGS. 18A and18B in that the length of the resonant conductor 68 is less than that ofone side of the metal film 65 defining a radiator. In the example ofFIG. 19A, the resonant conductor 68 is provided along one side of themetal film 65. In the example of FIG. 19B, the resonant conductor 68 isprovided at a location that is separated from an area in which the metalfilm 65 is provided.

Even with the above-described relationship, when the printed wiringsubstrate 80 and the metal film 65 have relatively large areas and aresonance frequency caused by the metal film 65 is relatively low, theresonant frequency of the resonant conductor 68 may be set to be in thevicinity of the operating frequency of an RFID. Thus, a high gain isobtained.

As shown in FIG. 20, the resonant conductor 68 has a meandering lineshape and the entire resonant conductor 68 is arranged along one side ofthe metal film 65.

According to the above-described configuration, because the resonatorlength may be increased even when the profile of the resonant conductor68 is relatively short, a high gain may be obtained when it is resonatedat a relatively low frequency.

As shown in FIGS. 21A and 21B, the resonant conductor 68 is longer thanone side of the metal film 65 that functions as a radiator. In addition,a main portion 6 of the wireless IC device is disposed at a locationshifted from the approximate center of one side of the metal film 65that functions as a radiator. In this case, as shown in FIGS. 21A and21B, the approximate center of the resonant conductor 68 must bearranged adjacent to the loop electrode of the main portion 6 of thewireless IC device.

As shown in FIG. 21A, a metal film 69 arranged to provide another groundelectrode or another circuit is provided in a margin at a locationadjacent to the metal film 65. In addition, as shown in FIG. 21B, theresonant conductor 68 is arranged along two sides of the metal film 65.

In this manner, even when the pattern of the metal film 65 thatfunctions as a radiator is relatively small, a high gain is obtained byproviding the resonant conductor 68 having a length that provides anecessary resonant frequency.

Twelfth Preferred Embodiment

FIG. 22 is a view that shows the configuration of a wireless IC deviceaccording to a twelfth preferred embodiment of the present invention. InFIG. 22, the main portion 6 of the wireless IC device similar to thatshown in FIG. 18 is provided in each of two metal films 65A and 65B onthe upper surface of a printed wiring substrate 80. Then, a resonantconductor 68 is arranged so as to be coupled to both high-frequencydevices provided at the main portions 6 of the two wireless IC devices.That is, one resonant conductor 68 is preferably shared by twohigh-frequency devices.

For example, the printed wiring substrate 80 may include RFID tagshaving different frequency bands (for example, even in the same UHFband, a standard frequency in accordance with a destination) by beingseparated into the side at which a metal film 65A is provided and theside at which a metal film 65B is provided.

When the resonant conductor 68 is longer than one side of the metal film65 that functions as a radiator, the resonant conductor 68 maypreferably be easily shared as a resonator for a plurality ofhigh-frequency devices as described above. In addition, even when sharedfrequencies are different, the resonant frequency merely needs to be setto a frequency approximate the same as the frequencies used in theplurality of RFID tags.

When the resonant conductor 68 is used only in the manufacturingprocess, it will later be separated from the printed wiring substrate80. Thus, the mother printed wiring substrate does not have the wastedspace of an electrode pattern, and it is possible to prevent an increasein the cost due to the inclusion of the resonant conductor 68.

Thirteenth Preferred Embodiment

FIGS. 23A and 23B are views that show some configurations of a wirelessIC device according to a thirteenth preferred embodiment of the presentinvention. FIGS. 23A and 23B are plan views of a wireless IC device inwhich an RFID tag is provided on a printed wiring substrate.

As shown in FIGS. 23A and 23B, the metal film 65, which is used as aground electrode for another circuit, is provided on the upper surfaceof the printed wiring substrate 80. A main portion 6 of the wireless ICdevice similar to that shown in FIGS. 18A and 18B is provided at aportion of the metal film 65.

The configuration differs from the configuration shown in FIGS. 18A and18B in that only a portion in the vicinity of the approximate center ofthe resonant conductor 68 is arranged adjacent to the loop electrode ofthe main portion 6 of the wireless IC device. Depending on therelationship between the length of one side of the metal film 65 thatfunctions as a radiator and the length of the resonant conductor 68,portions near both ends of the resonant conductor 68 may be arranged ina shape so as to be located away from the metal film 65 as describedabove.

Fourteenth Preferred Embodiment

FIG. 24 is a plan view that shows the configuration of a wireless ICdevice according to a fourteenth preferred embodiment of the presentinvention. The configuration differs from the configuration shown inFIGS. 18A and 18B in that resonant conductors 68A and 68B arerespectively arranged along two sides of the metal film 65.

One resonant conductor 68A is strongly coupled to a high-frequencydevice provided at the main portion 6 of the wireless IC device. Theother resonant conductor 68B is located adjacently along the metal film65. Thus, the other resonant conductor 68B is coupled to thehigh-frequency device via an electromagnetic field distributed in themetal film 65. Both of the resonant conductors 68A and 68B operate as atwo-end-open half-wavelength resonator.

The plurality of resonant conductors 68 are not limited to beingarranged along two opposite sides of the metal film 65, and may bearranged along sides of the metal film 65, which are substantiallyperpendicular to each other.

Fifteenth Preferred Embodiment

FIG. 25 is a plan view that shows the configuration of a wireless ICdevice according to a fifteenth preferred embodiment of the presentinvention. In the tenth to fourteenth preferred embodiments, theresonant conductor is provided on the printed wiring substrate, whereasin the fifteenth preferred embodiment, a metal case of a device, onwhich the wireless IC device is mounted, or a mounting destinationcomponent 81, such as a mounting component, defines the resonantconductor.

With the above-described configuration, the metal case of the device, onwhich the wireless IC device is mounted, the mounting component, orother suitable component, functions as a resonator. Thus, it is notnecessary to provide a resonant conductor on the printed wiringsubstrate. This can reduce the size of the printed wiring substrate 80and thus, the cost may be reduced.

Sixteenth Preferred Embodiment

In the sixteenth preferred embodiment, a resonant conductor is fixed,and at the time when a printed wiring substrate is conveyed along aprocess line, the printed wiring substrate communicates with areader/writer.

FIG. 26 is a plan view that shows the configuration of a wireless ICdevice according to the sixteenth preferred embodiment of the presentinvention. In FIG. 26, a process line installed conductor 82 is arrangedalong the process line along which the printed wiring substrate 65 isconveyed. The reader/writer is arranged at a location relatively closeto the process line installed conductor 82 (but not necessarily adjacentthereto).

A main portion 6 of a wireless IC device similar to that shown in FIGS.18A and 18B is provided on the metal film 65 of the printed wiringsubstrate 80.

When the printed wiring substrate 80 is conveyed along the process lineand the main portion 6 of the wireless IC device is located adjacent tothe process line installed conductor 82, the process line installedconductor 82 functions as a resonator that resonates at the frequency ofan RFID tag. Thus, it is possible to communicate with the reader/writerwith a high gain in this state.

According to the above-described configuration and communication method,because no resonant conductor is required on the printed wiringsubstrate, the area of a wirable portion increases. In addition, becauseit operates as an RFID tag only when the printed wiring substrate 80 islocated close to the process line installed conductor 82, it is possibleto communicate only with an RFID tag disposed at a specific location.That is, it is possible to selectively communicate only with a desiredRFID tag without communicating with an unintended RFID tag.

Seventeenth Preferred Embodiment

FIG. 27A is a perspective view of a cellular phone terminal providedwith a wireless IC device, and FIG. 27B is a cross-sectional view of amain portion of an internal circuit substrate. The power supply circuitsubstrate 4, on which the wireless IC chip 5 is mounted, is installed onthe circuit substrate 15 inside a cellular phone terminal, together withelectronic components 17 and 18. An electrode pattern 16 that spreads ina predetermined area is provided on the upper surface of the circuitsubstrate 15. The electrode pattern 16 is coupled to the wireless ICchip 5 via the power supply circuit substrate 4 so as to function as aradiator.

Alternatively, a wireless IC device may preferably be provided at ametal panel provided at the rear surface of an internal component (forexample, the liquid crystal panel) of the cellular phone terminal shownin FIG. 27A. That is, the metal panel may function as a radiator of anantenna by applying the wireless IC device shown in the first to seventhpreferred embodiments.

Note that it may be similarly applied to any articles having aconductive portion with a predetermined area, other than the abovedescribed preferred embodiments. For example, it may also be applied toa medicine or snack packages having a composite film including aluminumfoil, such as a press through package (PTP).

Eighteenth Preferred Embodiment

In the preferred embodiment shown in FIG. 9A, the metal film 65 thatfunctions as a radiator is formed of a sheet material or a platematerial, and the metal film 65 partially defines the cutout portion 66,so that the portion extending along the inner peripheral edge of thecutout portion 66 defines the loop electrode. When the above-describedconfiguration is applied to the printed wiring substrate, acharacteristic as an RFID tag varies depending on a circuit provided onthe printed wiring substrate. Thus, the degree of difficulty indesigning the printed wiring substrate increases. An eighteenthpreferred embodiment of the present invention eliminates this problem.

FIG. 28 is a plan view that shows the configuration of a component for awireless IC device according to the eighteenth preferred embodiment ofthe present invention. A mounting portion, on which an electromagneticcoupling module 1 is mounted, a matching circuit 67, and a loopelectrode 7 are provided on a printed wiring substrate 13, such as aglass epoxy substrate. The ends of the loop electrode 7 extend to an endof one side of the printed wiring substrate 13 as soldering electrodeportions indicated by A. The electromagnetic coupling module 1 ismounted on the printed wiring substrate 13 to define a component 111 fora wireless IC device.

FIG. 29 is a plan view that shows a wireless IC device that includes thecomponent for a wireless IC device according to the eighteenth preferredembodiment. As shown in FIG. 29, the component 111 for a wireless ICdevice is soldered to a location at which the loop electrode of theprinted wiring substrate 80 will be provided. When a resist film iscoated on the electrodes of the printed wiring substrate 80, the resistfilm is peeled off with a router, or other suitable device, to be readyfor soldering. In this state, characteristics, such as a readingdistance as an RFID tag, and an influence of ambient wires, a casing, orother factors, when assembled to a device are checked.

When an optimum location is determined based on the results of checkingof the characteristics, as shown in FIG. 30, the matching circuit 67 anda mounting portion for the electromagnetic coupling module 1 areprovided at a location in the vicinity of a location at which thecomponent 111 for a wireless IC device is assembled, within a groundelectrode formation area on the printed wiring substrate 80, and thenthe electromagnetic coupling module 1 is mounted. By so doing, the mainportion 6 of the wireless IC device is provided on the printed wiringsubstrate 80.

Nineteenth Preferred Embodiment

FIGS. 31A and 31B are plan views that show the configuration of acomponent for a wireless IC device according to a nineteenth preferredembodiment of the present invention and the configuration of a wirelessIC device provided with that component.

As shown in FIG. 31A, the printed wiring substrate 80 has a cutoutportion C provided at a location at which the component 111 for awireless IC device is assembled, and then as shown in FIG. 31B, thecomponent 111 for a wireless IC device is assembled to the location viasoldering. Soldering should be performed over the entire portions atwhich the electrodes contact.

With the above-described configuration, the state in which the component111 for a wireless IC device is assembled is closer to the final shapethan that in the preferred embodiment shown in FIG. 29. Thus, moreaccurate design may be performed.

Twentieth Preferred Embodiment

FIGS. 32A and 32B are plan views that show the configuration of acomponent for a wireless IC device according to a twentieth preferredembodiment of the present invention. FIG. 33 is a plan view that showsthe configuration of a wireless IC device provided with the componentfor a wireless IC device.

In this preferred embodiment, soldering electrode portions 88 areprovided on the rear surface of the component for a wireless IC device,and are preferably connected to the loop electrode 7 on the frontsurface via through-holes 87, for example. As shown in FIG. 33, thesoldering electrode portions 88 are soldered to the ground electrode ofthe printed wiring substrate 80.

In this manner, by providing the soldering electrode portions 88 on therear surface, even when the location at which the ground electrode isprovided does not extend to the edge of the printed wiring substrate 80,it may be easily mounted on the printed wiring substrate 80.

Twenty-First Preferred Embodiment

FIG. 34 is a plan view that shows the configuration of a component 113for a wireless IC device according to a twenty-first preferredembodiment of the present invention. A mounting portion, on which theelectromagnetic coupling module 1 is mounted, the matching circuit 67,and the loop electrode 7 are provided on a printed wiring substrate 13,such as a glass epoxy substrate, for example. The loop electrode 7differs from the preferred embodiment shown in FIG. 28 in that the endsof the linear electrode are electrically connected to define a loopelectrode.

The electromagnetic coupling module 1 is mounted on the printed wiringsubstrate 13 to define the component 113 for a wireless IC device. Thecomponent 113 for a wireless IC device, as in the case of the one shownin FIG. 29 or FIGS. 31A and 31B, is assembled to the printed wiringsubstrate.

In the component 113 for a wireless IC device, the loop electrode 7 isnot significantly influenced by the soldering, and highly accuratedesign with less fluctuations in the impedance may be achieved. Inaddition, when it is used as an electronic component, variations incharacteristics are reduced.

Note that in the above-described preferred embodiments, the wireless ICof the electromagnetic coupling module preferably utilizes the wirelessIC chip. However, preferred embodiments of the present invention are notlimited to ones using the wireless IC chip. For example, an organicsemiconductor circuit may be provided on a substrate to define thewireless IC.

While preferred embodiments of the present invention have been describedabove, it is to be understood that variations and modifications will beapparent to those skilled in the art without departing the scope andspirit of the present invention. The scope of the present invention,therefore, is to be determined solely by the following claims.

What is claimed is:
 1. An article comprising: a conductive member; ahigh-frequency device including a wireless IC chip; a loop electrodeconnected to the wireless IC chip; wherein the loop electrode is definedby at least one of a portion of the conductive member of the article ora separate conductive member that is different from the conductivemember of the article and coupled to the conductive member of thearticle; and the conductive member of the article defines a radiationelectrode that radiates an electromagnetic field.
 2. The articleaccording to claim 1, wherein the loop electrode is defined by a cutoutportion at an edge of the conductive member of the article; and thehigh-frequency device is arranged at the cutout portion and is coupledto the conductive member of the article at the cutout portion of theconductive member.
 3. The article according to claim 1, wherein the loopelectrode is provided at a mounting portion of the article at which thehigh-frequency device is mounted, such that a loop plane of the loopelectrode is arranged in a direction of a plane of the radiationelectrode.
 4. The article according to claim 3, further comprising: amatching circuit provided between the mounting portion of the articleand the loop electrode; wherein the matching circuit directlyelectrically connects the high-frequency device with the loop electrode.5. The article according to claim 1, further comprising at least oneresonant circuit provided in the article.
 6. The article according toclaim 5, wherein a resonant frequency of the at least one resonantcircuit corresponds to a frequency of a signal exchanged by theradiation electrode.
 7. The article according to claim 1, furthercomprising: a resonant conductor having a resonant frequency that isequal to an operating frequency of the high-frequency device; whereinthe resonant conductor is coupled to the high-frequency device.
 8. Thearticle according to claim 7, wherein the resonant conductor is arrangedparallel to an edge portion of the radiation electrode.
 9. The articleaccording to claim 7, wherein the resonant conductor has a length thatis equal to a side of the radiation electrode that is located adjacentto the resonant conductor.
 10. The article according to claim 7, whereinthe resonant conductor is arranged such that a center portion of theresonant conductor is located adjacent to a location of thehigh-frequency device.
 11. The article according to claim 7, wherein aplurality of the high-frequency devices are provided, and the resonantconductor is coupled to each of the plurality of high-frequency devices.12. The article according to claim 7, wherein the resonant conductor isseparable from the conductive member of the article that defines theradiation electrode.